When starting lens sorting, which two lenses are used?

When starting lens sorting, which two lenses are used?

• A. Two plus lenses
• B. Plano and plus lens
• C. A plus lens of +2.50 D and a minus lens
• D. Two minus lenses

Answer: (C)

Starting lens sorting needs a pair that gives a comfortable yet informative starting point for binocular testing. A plus lens of +2.50 D is used because it eases the eye’s accommodation a bit without removing all focusing effort, providing a clear starting view. Paired with a minus lens, this combination introduces a controlled amount of negative power so you can evaluate how the eyes respond when accommodation is challenged in the opposite direction and begin to distinguish hyperopic or accommodative issues from myopic ones. This mix creates a useful baseline from which you can refine the lenses toward neutral clarity and stable fusion. Using two plus lenses wouldn’t probe vergence and accommodation in both directions, using rather weak or no negative power would miss important responses, and two minus lenses would push the system in the opposite, less informative direction.

Starting lens sorting needs a pair that gives a comfortable yet informative starting point for binocular testing. A plus lens of +2.50 D is used because it eases the eye’s accommodation a bit without removing all focusing effort, providing a clear starting view. Paired with a minus lens, this combination introduces a controlled amount of negative power so you can evaluate how the eyes respond when accommodation is challenged in the opposite direction and begin to distinguish hyperopic or accommodative issues from myopic ones. This mix creates a useful baseline from which you can refine the lenses toward neutral clarity and stable fusion. Using two plus lenses wouldn’t probe vergence and accommodation in both directions, using rather weak or no negative power would miss important responses, and two minus lenses would push the system in the opposite, less informative direction.